So it seems like i get a new probably every time i drive my car. Last week i just changed out the starter and got it to finally start.
Now a new problem has spring up.

Today i fired it up after letting it sit a week, drove it about 5 miles and i decided to shift into fourth gear and i half throttled it with about 11psi.
I let off the gas and started to slow down and suddenly my fuel ratio jumped to lean at about 16.0+.
After scanning the engine i found that it's misfiring in cylinder 1.
I swapped the coilpacks around and it stayed in cylinder 1.
Then i swapped the spark plugs around and it stayed in cylinder 1.
I have a icm delete and a 2.0t coilpack upgrad so it can't be the ICM.


After i cleared the codes the A/F Ratio dropped to around 14.7 but was still misfiring consistently.


Anyone have any ideas?

 

spike in afr seems like a fuel issue to me if its attached to a misfire condition. since its confined to cylinder 1 i'd swap inejector 1 out with #2 and see it the misfire follows. which injectors you running btw?

 

Good idea! I'll have to do that in the morning.
I'm running 830cc Lucas Fuel Injectors.
Bought here 79 LB, 830cc Lucas Fuel Injector, High Impedance - 034Motorsport | Performance Parts for Audi, Porsche, and Volkswagen

 

yeah swap them out. but you could save yourself the trouble by ohming it out. dont quote me on this, but it should come out to somewhere around 12 or 13 ohms. i'm sure you could find the spec on it online. if they ohm out, it could just be dirty. if it doesnt ohm out, well theres your problem

edit:the spec on 750cc is 12 ohms, so theyve gotta be close to that, if not the same.

 

Tested them today with multi meter, they all read 12.1 across the board
I swapped the injectors, and it did not follow the injector.
I will check out the wiring harness for signs of wear, but it seems to be pretty intact and the shielding around it is not penetrated or cracked.
My vacuum is at -19 which is normal.
And this morning it is back to running lean.
In the 16+ A/F Ratio.

 

Can you see what happens when you unplug your MAF?

 

PROBLEM SOLVED
I swapped in a untuned ECU just to see if it changed and it did, it stopped misfiring.

So i put the old ECU back in and reflashed it. Started the car up and it was misfiring let it sit for about 20 seconds and the misfire disappeared.

Probably one of the more strange issues i've come across while owning this car.

 

they can get weird. i guess your tune just had a bug in it.